Illustration depicts typical installation of built-in 11-900 units. If you are attempting to install it in a body that is enclosed or covered, the installer is responsible to provide adequate and proper air flow to ensure proper unit operation and to adhere to unit safety requirements. The unit requires a minimum of 1600CFM ambient air flow to the air inlet. Engine heat and exhaust must be evacuated from the enclosure to prevent overheating and other safety issues. Contact Goodall to determine if additional consideration needs to be given to provide adequate ventilation.